While helping with some amphibian translocation work last autumn, I was told that adult toads could be sexed by rubbing their bellies. The "tickled" males would squeak, but the females would not. We did try this and found that >75% of them did in fact squeak. This would indicate that a high proportion of the toads in the area were males; could this be true? I am slightly sceptical of the accuracy of this method. I would be interested to know if anyone has used this method before or knows any more about it. Can female toads squeak too?

Comments

This is a reasonably reliable method to distinguish male and female toads. The males' squeak is what it know as a 'release call' and is primarily used to when a male toad is grasped by another male in a mating frenzy (they will try it on with anything - toads, frogs, fish...). However, female toads in the genus Bufo do seem to have a release call but from what I can determine it is inaudible and sensed via vibrations. Also, females of other frog and toad species do have an audible release call. I'm not sure whether vocalisations play a part in a defensive response to predators.

Common toads are quite hard to sex, especially outside of the breeding season. During the breeding season the males develop dark nuptial pads on the inner toes of their forearms. The males' throats are usually darker too and they are generally smaller. However, these can be difficult unless you have a male and female side by side.

It's interesting to know about their release calls. There was definitely a knack to the toad tickling; it was more effective rubbing the upper part of the trunk by the forelimbs. I can see that it might be easy to mistake an individual for a female if it doesn't squeak straight away because some males were quite reluctant to squeak.